My rankings are as follows:
keriostar: Simple, effective, and addictive.
Jakub: Ingenious idea, and by far the best graphics. I think it gets too hard too fast, but still a great game.
Victor: Boat should be faster, and also I can hardly see the bubbles, so I think they should have a color that contrasts better. Neat idea though.
Kibiz0r: Crazy difficulty curve! Way too dang easy, then suddenly insane.
CGamesPlay: Well, it's not a game, so... You should upload a revised version that turns this into a game somehow. It could be fun.
I've turned my thing into an actual game where you can win and lose; I'll upload the revised version in a few minutes. The idea was going to be that you try to fall, and avoid getting scraped off the top of the screen. But per CGamesPlay's suggestion, in the revised version you jump and I've made it the other way around.
And yeah, keriostar and I are friends. I really do enjoy his game the most though, but Jakub's is a close second.